The pictures above show the fit of race-level
electronics and battery pack. Note how close to the centre
of the car all the equipment fits. Cooling slots provide
as much air as possible to the battery pack.

Aluminium pivot joints are used to adjust and hold hinge pins.
aluminium threaded shock bodies, new lower spring perches and
aluminium clamp-style wheel hex adapters are standard for a precise
fit and feel. aluminium spacers are provided with the Pro 4 kit for
adjusting the roll centre and width of the car.

New for HPI is the standard 6-ball bearing steering assembly,
providing a slop-free steering setup. New ball cups and socketed
ball ends are also included to eliminate steering slop. Ackerman
can be easily adjusted by moving the steering links to optional
holes on the woven graphite steering plate.

The battery is positioned as close as possible to the shaft, to
put the most weight down the centerline of the car. The Pro 4 will
be able to fit any standard stick-type or side-by-side battery pack
with the included battery rails and strap.

The rear ball differential uses carbide diff balls and bevel
gears for maximum efficiency and durability. A front one-way
differential will be provided with the car.

In this picture you can clearly see the extremely low centre of
gravity (CG) that is provided by the Pro 4 design. Also, the
drivetrain sits as low as possible in the car, something not
possible with belt drive cars.

The Pro 4 was designed with an all-new
shaft drive drivetrain, optimised
suspension set up, twin deck C/F chassis
and perfected ackerman steering geometry for all
types of track layout's and racing conditions. The most noticeable
change is to the drive-train which utilises a highly efficient
shaft-drive 4wd transmission. Back-to-back track testing revealed
the benefits of low maintenance & fast
acceleration that a shaft drive transmission offers. The
RS4 Pro 4 will be a self-assembly kit form with
key items like the radio, ESC, body and tyres left to the choice of
the driver. The Pro 4 uses the highest quality
materials & will have an amazing
specificationto make it a force at the highest level of
competition.

Purple Anodised Aluminium Motor Mount &
Lightweight Driveshaft

Our HPI Team Drivers will be racing the Pro 4 at all major
touring car races as soon as the car is available - ensuring
trackside factory support, Team Set-up's and the essential,
continued development of the platform to keep the Pro 4 at the top
of the winning circle.